Portable printing or writing devices, and more specifically, portable printing devices used in the medical field are known. Typically, portable printing devices are integrated in, or otherwise attached to portable medical devices used to monitor patient data, such as heart rate, blood pressure, blood oxygenation, respiration, brain activity, and the like. The printing devices enable the physician, nurse, medical technician or other healthcare worker (collectively “clinician”) to print a hard copy of the patient data, which can be useful in studying and documenting changes in the patient's condition.